Rotatable suturing member

ABSTRACT

A suturing member and method of forming the suturing member on an implantable device, as a heart valve. The suturing member has a porous fabric cover surrounding a semi-rigid plastic core. An annular sleeve of heat shrinkable plastic material located within the cover holds the cover in assembled relation with the device in a manner which allows for rotation of the device after the suturing member has been attached to the heart tissue. In the method of forming and mounting the suturing member on the device, the suturing member is shaped and cured on the device with the use of a mold. The mold is heated to cure the plastic core of the suturing member and bond the core to the inner surface of the cover.

United States Patent [1 1 Anderson ROTATABLE SUTURING MEMBER [75]Inventor: Lawrence Anderson, Minneapolis,

Minn.

[73] Assignee: Medical Incorporated, Minneapolis,

Minn.

[22] Filed: Oct. 9, 1973 21 Appl. No.: 404,516

Related US. Application Data [60] Division of Ser. No. 279,936, Aug. 11,1972, Pat, No. 3,781,969, which is a continuation-impart of Ser. No.235,502, March 17, 1972, Pat. No. 3,763,548.

Child 3/1 X Child 3/1 Primary Examiner-Ronald L. Frinks [57] ABSTRACT Asuturing member and method of forming the suturing member on animplantable device, as a heart valve. The suturing member has a porousfabric cover surrounding a semi-rigid plastic core. An annular sleeve ofheat shrinkable plastic material located within the cover holds thecover in assembled relation with the device in a manner which allows forrotation of the device after the suturing member has been attached tothe heart tissue. In the method of forming and mounting the suturingmember on the device, the suturing member is shaped and cured on thedevice with the use of a mold. The mold is heated to cure the plasticcore of the suturing member and bond the core to the inner surface ofthe cover.

21 Claims, 16 Drawing Figures PATENTEU JAN 1 4 I975 sum 2 BF ROTATABLESUTURING MEMBER CROSS REFERENCE TO RELATED APPLICATION:

This application is a division of U.S. application Ser. No.279,936 filedAug. 11, 1972, now U.S. Pat. No. 3,781,969. Application Ser. No. 279,936is a continuation-in-part of U.S. application Ser. No. 235,502, filedMar. 17, 1972, now U.S. Pat. No. 3,763,548.

BACKGROUND OF THE INVENTION Clinical uses of prosthetic devices havingsuturing members for attaching the devices to tissue show that it isadvantageous to move the device relative to the suturing member afterthe suturing member has been connected to the tissue. Pivoting discvalves, as disclosed by Kaster in U.S. Pat. No. 3,476,143, have valvingdiscs that angularly move to open and closed positions. During theimplanting procedure, it is often desirable to adjust the angularposition of the valve after it has been implanted. The base of the valveis rotated relative to the suturing member secured to the heart tissueto orientate the disc away from calcifications that could interfere withthe free movement of the disc. The valve base is rotated relative to thesuturing member with a holder or handle used to position the valveduring the implant procedure. Heretofore, in order to permit angularorientation of the valve after implanting, the suturing member wasprovided with a relatively loose fit on the valve base. This looserelationship between the suturing member and the valve base isundesirable as in use the valve may shift or slide relative to thesuturing member and blood could accumulate and stagnate adjacent thevalve.

Suturing members are retained on the heart valve in a number of ways. Aclamp ring and wire is disclosed in U.S. Pat. No. 3,099,016 to hold thesewing ring on the valve base. Stainless steel and plastic rings encasedin porous material are used in U.S. Pat. No. 3,396,409 to hold theporous material on the base of the heart valve. Child in U.S. Pat. No.3,623,212 discloses a suturing member for implantable devices and amethod of making the suturing member on the device. The cover is held onthe valve base with a plurality of cords or threads. The threads arewould in a relatively close and tight relationship and prevent effectiverotation of the valve base relative to the suturing member once thethreads are tied. The cords do not provide for substan tially evenholding force across the entire width of the suturing member, wherebyportions of the suturing member can separate from the valve base.

SUMMARY OF THE INVENTION The invention is directed to a suturing memberfor implantable devices, as heart valves, and a method of making thesuturing member on the device. The suturing member is an annular sewingring or collar that is mounted on the device in a manner that allows forrotation of the device after the suturing member has been attached tothe tissue. The suturing member has a cover of biologically inert porousmaterial for accommodating live tissue ingrowth, or fibrosis, betweenthe tissue and the porous material. The cover surrounds a core ofplastic material bonded to the inner surface of the cover to confinebody fluids and blood to the cover. Located within the cover is anannular sleeve or tubular member of heat shrinkable plastic material.The sleeve is heat shrunk to provide a uniform contraction force to holdthe suturing member on the device. A plurality of cords surround thesleeve to insure that the entire width of the sleeve holds the cover infull engagement with the device. The suturing member is formed or madeon the device by holding a cylindrical fabric cover on the device withthe annular sleeve. The cover can be a seamless cylindrical fabric.After the sleeve is heat shrunk the cords are wound around the sleeve.The plastic material is then enclosed in the cover. The suturing memberis then shaped and heat cured in a mold. During heat curing of the core,the sleeve is further heat shrunk and the core is bonded to the insideof the cover.

An object of the invention is to provide an implantable device with asuturing member that permits movement of the device after the suturingmember has been attached to the tissue. Another object of the inventionis to provide a suturing member that does not separate fromthe device,but at the same time will permit rotation of the device relative to thesuturing member. A further object of the invention is to provide amethod of making a suturing member on a device which uniformly holds thesuturing member on the device and bonds the core material to the coverof the suturing member. Still another object of the invention is toprovide a suturing member which can be formed on a device in a varietyof shapes and which can be universally applied to many types ofimplantable devices.

IN THE DRAWINGS FIG. 1 is a proximal plan view of a heart valve inassembled relation with the suturing member of the invention;

FIG. 2 is a sectional view taken along the line 22 of FIG. 1;

FIG. 3 is an enlarged sectional view of a part of the valve base andsuturing member;

FIG. 4 is a plan view of a blank of the fabric cover of the suturingmember;

FIG. 5 is a perspective view of the fabric cover in cylindrical form;

FIG. 6 is a sectional view of part of the valve base showing the coverand heat shrunk sleeve surrounding the cover;

FIG. 7 is a sectional view similar to FIG. 6 showing the cords woundaround the sleeve;

FIG. 8 is a sectional view similar to FIG. 7 showing the plastic corematerial enclosed within the cover;

FIG. 9 is a sectional view of the valve and suturing member located in ashaping and curing mold;

FIG. 10 is a side elevational view of a cylindrical seamless fabriccover used in a modified suturing mem ber of the invention;

FIG. I] is a section view taken along line llll of FIG. 10;

FIG. 12 is a perspective view of the seamless fabric cover;

FIG. 13 is a sectional view of part of the valve base showing the coverand heat shrunk sleeve surrounding the cover;

FIG. 14 is a sectional view similar to FIG. 13 showing the cords woundaround the sleeve;

FIG. 15 is a sectional view similar to FIG. 14 showing the plastic corematerial enclosed within the cover; and

FIG. 16 is a sectional view of the valve and suturing member located ina shaping and curing mold. Referring to the drawings, there is shown inFIGS. 1 through 3 an implantable device, indicated generally at 20, forcontrolling the flow of a fluid. Device is a heart valve adapted for usein a human heart. Other types of implantable device can be used with thesuturing member of the invention. The following description is limitedto a pivoting disc heart valve having the suturing member of theinvention. Device 20 has a base or annular housing 21 associated with afree floating disc or occluder 22 to control the flow of blood throughvalve passageway 23. Disc 22 is a valving member that angularly movesfrom a closed position, shown in full lines in FIG. 2, to an openposition, shown in broken lines, and back to the closed position inresponse to differential blood pressureson opposite sides of the valve.

Disc 22 is retained in a free floating relationship with the basewhereby it is free to rotate about its center and has limited lateralshifting movement as it angularly moves between its open and closedpositions. The disc pivots about an off-center or eccentric axis withrespect to the diameter of the disc whereby, when the disc is in theopen position, there is substantially unrestricted central flow of bloodthrough the valve passageway 23. When disc 22 is in its open position,separate portions of the disc extend above and below the valve base.Valve housing 21 is an annular member having annular outwardly directedupper and lower flanges 24 and 25, respectively. A circular cylindricaloutside wall 26 extends between flanges 24 and 25 and forms therewith anoutwardly open groove for accomodating a sewing ring or suturing member,indicated generally at 27. Wall 26 has a slight outwardly divergingtaper in the direction of the flow of blood through the passageway 23.Preferably the taper is 6, the inside face of flange 24 is and theinside face of flange 25 is 25 relative to the longitudinal axis ofpassageway 23. Other angles and size relationship between flanges 24 and25 and wall 26 can be used. Suturing member 27 provides structure forreceiving sutures used to attach the valve to the heart tissue. Suturemember 27 is mounted on valve housing 21 in a manner so that the housingcan be rotated relative to the suturing member after the su turingmember has been attached to the heart tissue. This permits the surgeonto adjust the angular position of the valve disc after it has beenimplanted. Disc 22 can be orientated away from calcifications which mayinterfere with the free movement of the disc.

Valve housing 21 has an inside wall 28 surrounding the passageway 23 tothe housing. Disc 22 has an uninterrupted outer peripheral edge 29 whichcooperates with inside wall 28 when the disc is in the closed positionto substantially block reverse flow of blood through passageway 23. Thediameter of disc 22 is slightly smaller than the diameter of opening 23.This leaves a small annular space 31 between the outer peripheral edge29 and the adjacent circumferential portion of the inside, wall 28 ofthe valve housing. This space 31 permits limited reverse or retrogradeflow of blood through the valve opening 23 when the disc 22 is in theclosed position. Retrograde flow of blood prevents stagnation of bloodin pockets or pools since the blood is continuously moving through thepassageway 23.

Disc 22 has a circular configuration with generally flat upper and lowersides which are joined by the uninterrupted outer peripheral edge. Thedisc has a substrate 32 covered with a skin or coating 33. Coating 33 isa hard, biologically inert, wear resistant material such as pyrolyticcarbon.

A first pair of pivot means indicated generally at 34 and a second pairof pivot means indicated generally at 36 cooperate with the disc tocontrol its pivotal movement and limit its open and closed positions.The pairs of pivot members provide disc 22 with a pivot axis that isoffset from the diameter of the disc so that when the disc is in theopen position there is free central flow of blood through passageway 23.The pivot axis of the disc generally follows an imaginary chord lineapproximately an equal distance between the center of passageway 23 andthe portion of wall 28 measured along a transverse diametrical line. Thepivotal axis of the disc 22 will vary or shift relative to the center ofthe disc during the opening and closing episodes of the disc since thedisc is free for limited movement in its plane.

The first pair of pivot means 34 comprise an upper, or distal, pivot 37and a lower, or proximal, pivot 38 located adjacent oppositecircumferential portions of the disc 22 and projected into passageway23. The second pair of pivots comprise an upper, or distal, pivot 39 anda lower, or proximal, pivot 41 located adjacent opposite portions of thedisc and extended into passage 23. The pivots 37, 38 and 39, 41 arepairs of projections, elements or legs having surfaces which function asful crums and stops for the disc during its opening and closingmovements. As shown in FIG. 2, the pivot 37 has fulcrum surfaces 37Aengageable with the disc during the opening episode of the disc. Pivotmember 38 has fulcrum surfaces 38A which engage the disc during theclosing episode of the disc. The fulcrum surfaces of the pivotscooperate with separate portions of the disc 22 to define the pivotingand free floating movement of the disc 22.

Disc 22 is retained in assembled relation with the valve housing 21 witha pair of upwardly and forwardly projected arms 42 and 43. Arms 42 and43 have inwardly facing guide surfaces which provide a path of movementfor the disc during its opening and closing movements. The arms projectupwardly in the direction of the pivotal movement of the disc and haveouter ends that are turned inwardly to prevent escape of the disc whenit is in its open position, as shown in broken lines in FIG. 2.

When the disc is in its closed position, it rests on the upper fulcrumsurfaces of the proximal pivots 38 and 41 and an abutment or stop 44. Asshown in FIG. 1, stop 44 extends inwardly into passageway 23 and is located approximately midway between the pivots 38 and 41. The disc, whenin the closed position, is inclined at an angle relative to thelongitudinal axis of passageway 23. Preferably, the angle isapproximately 18 with respect to a transverse plane normal to thelongitudinal axis of passageway 23. When the disc is in the openposition, it is inclined approximately to with respect to the transverseplane.

Referring to FIG. 3, the suturing member 27 has a cover 46 of wovenporous material made of synthetic fibers, as Teflon or Dacron cloth. Thematerial of cover 46 is biologically inert and does not deteriorate withtime. Cover 46 preferably is an interlaced or knitted fabric having amesh or spaces into which living tissue grows to form a permanent unionbetween the suturing member and the tissue independent of the suturesapplied by the surgeon. Cover 46 surrounds a core 47 of semi-rigidplastic material. Core 47 is a pliable plastic in the uncured statewhich is compatible with human tissue and body fluids. Furthermore, core47 is sterilizable, biologically inert, non-irritating and non-toxic tobody fluids andtissues. On curing of the plastic core material withheat, a bond is achieved between the inside surface of the cover and theplastic to eliminate all pockets or separations of the cover from theplastic core which could collect blood and other body fluids. The corematerial preferably is a plastic, such as Dow-Corning Silastic,"fluorosilicone rubber, or a similar synthetic resinous plastic material.This core material cures at a relatively low temperature to asemi-rigid, non-elastic plastic which retains its molded shape. The molddetermines the ultimate shape of the suturing member, so that bothmitral and aortic suturing members can be made with different shapedmolds. Suturing member 27 has a mitral configuration with an outwardlyextended flange 50. The proximal side of flange 50 has an upwardlycurved suface 50A, as viewed in FIGS. 2 and 3. The thickness of flange50 decreases toward the outer peripheral edge making the outer sectionof flange 50 more flexible and easier to suture.

As shown in FIG. 3, the end sections of the cover 46 are securedtogether with a stitch 48. The ends of cover 46 are turned inwardly sothat the outside surface of the cover is smooth. Cover 46, being porous,permits tissue ingrowth so that in time the suturing member will befirmly attached to the heart tissue.

Cover 46 has running or box stitches 49 in the portion adjacent theoutside wall 26 of the valve housing. The ends of the thread forming thestitches 49 are knottedtogether to insure that cover 46 is secure on thevalve housing. A continuous, circular sleeve 51 is located between core47 and a portion of the cover adjacent the outside wall 26 of thehousing. Sleeve 51 is a tubular member or ring of heat shrinkablematerial, as Teflon. Sleeve 51 has a width which substantially fills thegroove in the valve housing between flanges 24 and 25. The upper andlower portions of sleeve 51 have enlarged annular end beads 52 and 53.Beads 52 and 53 have outwardly open and continuous grooves 54 and 56respectively. The top edge 51A of bead 52 has outwardly and upwardlydirected taper which substantially follows the slope of the insidesurface of flange 24. Bead 53 has a lower edge 51B that has a taperwhich substantially follows the slope of the inside offlange 25. Theheat shrunk plastic sleeve 51 provides uniform contracting and holdingforces which allows rotation of the valve base relative to the suturingmember 27.

A row of threads or surgical string wrapped around sleeve 51 extendsbetween beads 52 and 53. A thread 57A is located in groove 54 of bead52. In a similar manner, thread 573 is located in groove 56 of bead 53.When threads 57A and 57B are tightened, they insure that cover 46 willremain in close fitting relationship with respect to the inner surfacesof flanges 24 and 25.

Referring to FIGS. 4 through 9, there is shown a method of making andassembling suturing member 27 on valve housing 21. As shown in FIG. 4,cover 46 is cut into a rectangular shape of a selected size, dependingon the size of the valve housing. For example, the cover material for anaortic valve can range from 72 mm X 16 mm to 108 mm X 26 mm and thematerial for a mitral valve can range from 72 X 18 mm to 110 X 26 mm.Preferably, the fabric is cut on a bias at a 45 angle. The fabric isthen formed into a cylinder or tube,

as shown in FIG. 5. The adjacent ends of the cover 46 are stitchedtogether with stitches 58, with the ends projected in an outwarddirection. Double box stitches 49 are placed through the mid-portion ofthe cylindri cal cover 46, with ends 49A and 49B extended on the outsideof the cover.

Referring to FIG. 6, the cover 46 is then placed about the valve housing21. The mid-portion of cover 46 carrying stitches 49 is locatedapproximately at the midpoint of outside wall 26. The ends 49A and 49Bare pulled and tied together. Sleeve 51 is then slipped over the coverand located in the groove between flanges 24 and 25. The plastic sleeve51 has a pre-shrunk size when it is placed over the cover 46. Sleeve 51is a tubular member that is initially pre-shrunk on a cylindricalmandrel to a selected diameter. After the sleeve has been shrunk on themandrel, grooves 54 and 56 are cut on the outer side and the angles or'tapers on edges 51A and 51B are cut. The sleeve is then removed fromthe mandrel and is of a size that slips over the cover 46 located aroundthe valve base. Heat is then applied to sleeve 51 ,to shrink it, therebyreducing its diameter and uniformly squeezing the cover 46 intoengagement with outside wall 26 of the valve housing 21.

Referring to FIG. 7, the cords 5 7 are then wrapped around sleeve 51.During wrapping, the cords are, at substantially uniform tension so thateven contracting force is applied to sleeve 51. The outer cords 57A and57B are placed in their respective grooves 54 and 56 and tied to firmlyhold the beads adjacent flanges 24 and 25.

Referring to FIG. 8, uncured core material 47 is placed around sleeve 51and enclosed in the cover 46. The ends of the cover are turned inwardlyand are secured together with continuous stitches 48. The uncured corematerial 47 can be formed into an elongated roll and uniformly placedaround sleeve 51. The plastic core material 47, being uncured, is in arelatively pliable and malleable state so that it can be uniformlyplaced about sleeve 51. Preferably, a roll of uncured plastic materialis weighed so "that a determinant amount of plastic material can beplaced within cover 46. The suturing member is now ready to be placed inthe mold for shaping or forming.

As shown in FIG. 9, the valve 20 is located in the curing mold 59. Thecenter portion of mold 59 has a chamber or cavity 61 for accommodatingthe valve. The upper portion of mold cavity 61 has an annular steppedgroove 62. Groove 62 is part of the cavity 61 defined by generallyupright circumferential surface or wall 63 and a generally horizontalsurface or wall 64, providing the forming or shaping surfaces for thesuturing member 27. Immediately adjacent the lower portion of surface 63is an annular step 66 which forms a positioning stop for the valve base21. Groove 62 of the mold 59 can have different shapes and sizes to formdifferent types and styles of suturing members.

In the formation of suturing member 27 on the valve base 21, valve 20 isplaced in chamber 61 with suturing member 27 pressed into the steppedgroove or cavity 62. As the suturing member is moved into the cavity,its shape conforms to the mold groove 62 to form its outwardly directedperipheral flange portion. The suturing member 27 is positioned ingroove 62 with a light force fit so that the inside of cover 46 is incontinuous engagement with the plastic core 47. An annular member orring 65 is placed over the suturing member 27. Ring 65 has a size andshape, as shown in FIG. 9, to form curved surface 50A when pressed intomold cavity 62. The entire valve structure and suturing member 27 areretained in mold cavity 61 with a flat cover or plate 67 which engagesring 65, holding it in firm engagement with surface 50A of suturingmember 27.

Plastic core material 47 is'cured by heating the mold for a period oftime. During heating, sleeve 51 will further heat shrink and corematerial 47 will bond to the adjacent inside surface of cover 46. Forexample, with core material of Silastic, the mold is heated in an ovenfor approximately 20 minutes at 250 F. Other temperatures and times areusable in accordance with the heat curing characteristics of theplastic. During the curing operation, plastic core material 47 does notflow into or penetrate the fabric of cover 46, whereby cover 46 retainsits porous characteristics and its ability to receive tissue ingrowth.

After suturing member 27 is formed and cured, the valve 20 along withsuturing member 27, is removed from mold 59. The relatively low curingtemperature does not have any harmful effects on the material of thesleeve 51 or the material of the valve base 21 and disc 22.

The beads 52 and 53 of sleeve 51 firmly hold the cover 46 in engagementwith the inside faces of flanges 24 and 25, thereby prohibitingundesirable flexing of the inner portions of the suturing member andseparation of the suturing member from the valve base. The sleeve 51places an even and substantially constant contraction or squeezing forceon the inner portion of cover 46 that engages valve housing 21. Thisforce is limited. The limits of the force are selected so that the valvehousing can be rotated relative to the suturing member.

Referring to FIGS. through 15, there is shown another method of makingand assembling suturing member 127 on valve housing 121. As shown inFIGS. 10 and 11, cover 146 is a seamless cylindrical member or tube cutto a length determined by the type, size and shape of the suturingmember. Cover 146 may be seamless tubular knitted or woven Dacron fabricor other biological inert materials having a mesh, spaces, or porosityenabling ingrowth of tissue soon after implantation. The seamless covereliminates the side seam, shown adjacent stitches 58 in FIG. 5, therebyproviding an even and continuous outer cover surface.

As shown in FIG. 12, double box stitches 149 are placed through themid-portion of the cylindrical cover 146, with ends 149A and 1498extended on the outside of the cover.

Referring to FIG. 13, the seamless cover 146 is then placed about thevalve housing 121. The mid-portion of cover 146 carrying stitches 149 islocated approximately at the mid-point of outside wall 126. The ends149A and 1498 are pulled and tied together. Sleeve is then slipped overthe cover and located in the groove between flanges 124 and 125. Theplastic sleeve 151 has a pre-shrunk size when it is placed over thecover 146. Sleeve 151 is a tubular member that is initially pre-shrunkon a cylindrical mandrel to a selected diameter. After the sleeve hasbeen shrunk on the mandrel, grooves 154 and 156 are cut on the outerside and the angles or tapers on edges 151A and 151B are cut. The sleeveis then removed from the mandrel and is of a size that slips over thecover 146 located around the valve base. Heat is then applied to sleeve151 to shrink it, thereby reducing its diameter and uniformly squeezingthe cover 146 into engagement with outside wall 126 of the valve housing121.

Referring to FIG. 14, the cords 157 are then wrapped around sleeve 15].During wrapping, the cords are at substantially uniform tension so thateven contracting force is applied to sleeve 151. The outer cords 157Aand 1578 are placed in their respective grooves 154 and 156 and tied tofirmly hold the beads adjacent flanges 124 and 125.

Referring to FIG. 15, uncured core material 147 is placed around sleeve151 and enclosed in the cover 146. The ends of the cover are turnedinwardly and are secured together with continuous stitches 148. Theuncured core material 147 can be formed into an elongated roll anduniformly placed around sleeve 151. The plastic core material 147, beinguncured, is in a relatively pliable and malleable state so that it canbe uniformly placed about sleeve 151. Preferably. a roll of uncuredplastic material is weighed so that a detcrmi' nant amount of plasticmaterial can be placed within cover 146. The suturing member is nowready to be placed in the mold for shaping or forming.

As shown in FIG. 16, the valve is located in the curing mold 159. Thecenter portion of mold 159 has a chamber or cavity 161 for accommodatingthe valve. The upper portion of mold cavity 161 has an annular steppedgroove 162. Groove 162 is part of the cavity 161 defined by generallyupright circumferential surface or wall 163 and a generally horizontalsurface or wall 164, providing the forming or shaping surfaces for thesuturing member 127. Immediately adjacent the lower portion of surface163 is an annular step 166 which forms a positioning stop for the valvebase 121. Groove 162 of the mold 159 can have different shapes and sizesto form different types and styles of suturing members.

In the formation of suturing member 127 on the valve base 121, valve 120is placed in chamber 161 with suturing member 127 pressed into thestepped groove or cavity 162. As the suturing member is moved into thecavity, its shape conforms to the mold groove 162 to form its outwardlydirected peripheral flange portion. The suturing member 127 ispositioned in groove 162 with a light force fit so that the inside ofcover 146 is in continuous engagement with the plastic core 147. Anannular member or ring 165 is placed over the suturing member 127. Ring165 has a size and shape, as shown in FIG. 16, to form curved surface Awhen pressed into mold cavity 162. The entire valve structure andsuturing member 127 are retained in mold cavity 161 with a flat cover orplate 167 which engages ring 165, holding it in firm engagement withsurface 150A of suturing member 127.

Plastic core material 147 is cured by heating the mold for a period oftime. During heating, sleeve 15] will further heat shrink and corematerial 147 will bond to the adjacent inside surface of cover 146. Forexample, with core material of Silastic," the mold is heated in an ovenfor approximately 20 minutes at 250 F. Other temperatures and times areusable in accordance with the heat curing characteristics of theplastic. During the curing operation, plastic core material 147 does notflow into or penetrate the fabric of cover 146, whereby cover 146retains its porous characteristics and its ability to receive tissueingrowth.

After suturing member 127 is formed and cured, the valve 120 along withsuturing member 127, is removed from mold 159. The relatively low curingtemperature does not have any harmful effects on the material of thesleeve 151 or the material of the valve base 121 and disc 122.

The beads 152 and 153 of sleeve 151 firmly hold the cover 146 inengagement with the inside faces of flanges 124 and 125, therebyprohibiting undesirable flexing of the inner portions of the suturingmember and separation of the suturing member from the valve base. Thesleeve 151 places an even and substantially constant contraction orsqueezing force on the inner portion of cover 146 that engages valvehousing 121. This force is limited. The limits of the force are selectedso that the valve housing can be rotated relative to the suturingmember.

I claim:

1. A suturing member mountable on a member having an outer annular walland outwardly directed flanges forming an annular groove and connectableto tissues of a living creature comprising: cover means including porousmaterial for accommodating live tissues to form a union between thesuturing member and the tissues, a continuous sleeve of heat shrunkplastic material located around an inner portion of said cover means tohold the suturing member in the annular groove in engagement with theannular wall and flanges of the member, said sleeve having opposite endportions with means to accommodate contracting force applying means,means located around said sleeve to apply a continuous contracting forceon the sleeve, said means including means cooperating with the means onthe opposite end portions of the sleeve to force the end portions towardthe flanges, and a core of cured plastic material located adjacent saidsleeve and surrounded by said cover means.

2. The suturing member of claim 1 wherein: said core material has anouter surface secured to the inner surface of the cover means.

3. A suturing member connectable to tissues of a living creaturecomprising: cover means including porous material for accommodating livetissues to form a union between the member and the tissues, a sleeve ofheat shrunk plastic material located around an inner portion of saidcover means, cord means wrapped around said sleeve, and a core of curedplastic material located adjacent said sleeve and surrounded by saidcover means, said sleeve having annular outwardly open grooves in theopposite end portions thereof, and continuous contracting means locatedin said grooves.

4. A suturing member connectable to tissues of a living creaturecomprising: cover means including porous material for accommodating livetissues to form a union between the member and the tissues, a sleeve ofheat shrunk plastic material located around an inner portion of saidcover means, cord means wrapped around said sleeve, and a core of curedplastic material located adjacent said sleeve and surrounded by saidcover means, said sleeve having annular enlarged bead means on theopposite end portions thereof, said bead means having outwardly opengroove means, means located in said groove means providing a contractingforce on the opposite end portions of said sleeve, said cord means beinglocated and confined to the space between said bead means.

5. A heart valve comprising: a valve base having spaced outwardlydirected flanges and an outer wall between said flanges forming agroove, a valve member selectively movable relative to said base to openand closed positions, means holding the valve member in assembledrelation with the base, a suturing member mounted on said base with aportion thereof located in said groove, said suturing member havingcover means including porous material for accommodating live hearttissue to form a union between the suturing memher and the heart tissue,a sleeve of heat shrunk material] holding a section of said cover meansin said groove and in uniform engagement with the flanges and outer wallof the base, said sleeve having opposite end portions with means toaccommodate contracting force applying means, cord means around saidsleeve providing a contracting and holding force on said sleeve. saidcord means including means cooperating with the means on the oppositeend portions of the sleeve to force the end portions toward the flanges,and a core of cured plastic material surrounding said sleeve andenclosed within said cover means.

6. The heart valve of claim 5 wherein: said core of plastic material issecured to the cover means and cord means.

7. A suturing member connectable to tissues of a living creaturecomprising: cover means including porous material for accommodating livetissues to form a union between the member and the tissues, a continuousannular sleeve of heat shrunk plastic material lo cated around an innerportion of said cover means, said sleeve having annular outwardly opengrooves in the opposite end portions thereof, and continuous contractingmeans located in said grooves, and cord means wrapped around saidsleeve.

8. A heart valve comprising: a valve base, a valve member selectivelymovable relative to said base to open and closed positions, meansholding the valve member in assembled relation with the base, a suturingmember mounted on an outer portion of said base, said suturing memberhaving cover means including porous material for accommodating liveheart tissue to form a union between the suturing member and the hearttissue, a sleeve of heat shrunk material holding a section of said coverin engagement with the outer portion of the base, said sleeve havingannular outwardly open grooves in the opposite end portions thereof,continuous contracting means located in said grooves, cord means aroundsaid sleeve providing a contracting and holding force on said sleeve,and a core of cured plastic material surrounding said sleeve andenclosed with said cover means.

9. A heart valve comprising: a valve base, a valve member selectivelymovable relative to said base to open and closed positions, meansholding the valve member in assembled relation with the base, a suturingmember mounted on the outer portion of said base, said suturing memberhaving cover means including porous material for accommodating livetissue for form a union between the suturing member and the hearttissue, a sleeve of heat shrunk material holding a section of said coverin engagement with the outer portion of the base, said sleeve havingannular enlarged bead means on the opposite end portions thereof, saidbead means having outwardly open groove means, means located in saidgroove means providing a contracting force on the opposite end portionsof said sleeve, cord means around said sleeve providing a contractingand holding force on said sleeve, said cord means being located andconfined to the space between said bead means, and a core of curedplastic material surrounding said sleeve and enclosed within said covermeans.

l0. A suturing member connectable to tissues of a living creaturecomprising: means for accommodating live tissues to form a union betweenthe member and the tissues, a continuous annular sleeve located aroundan inner portion of said means, said sleeve having opposite endportions, said end portions having means to accommodate means providingcontinuous contracting forces on said end portions, and means locatedaround said sleeve providing a contracting and holding force on saidsleeve, said means located around said sleeve including meanscooperating with the means of the op posite end portions providingcontinuous contracting forces on said end portions.

11. The suturing member of claim wherein: the end portions are enlargedbeads having outwardly open groove means, said means cooperating withthe end portions being located in said grooves.

12. The suturing member of claim 10 wherein: the means located aroundthesleeve comprise cord means wrapped around the sleeve.

13. The suturing member of claim 10 including: a core of plasticmaterial surrounding the sleeve and enclosed with the means foraccommodating live tissues.

14. A suturing member connectable to tissues of a living creaturecomprising: cover means including porous material for accommodating livetissues to form a union between the member and the tissues, a continuousannular sleeve of heat shrunk plastic material located around an innerportion of said cover means, said sleeve having annular enlarged beadmeans on the opposite end portions thereof, said bead means havingoutwardly open groove means, means located in said groove meansproviding a contracting force on the opposite end portions of saidsleeve, and cord means wrapped around said sleeve, said cord means beinglocated and confined to the space between said bead means.

15. A suturing member connectable to tissues of a living creaturecomprising: means for accommodating live tissues to form a union betweenthe member and the tissues, a sleeve located around an inner portion ofsaid means, means located about said sleeve to apply a continuouscontracting force on said. sleeve, said sleeve having outwardly opengrooves in the opposite end portions thereof, and means located in saidgrooves applying a continuous force on said end portions.

16. The suturing member of claim 15 wherein: said sleeve has annularenlarged bead means on the opposite end portions thereof, said beadmeans having the outwardly open grooves.

17. A heart valve comprising: a valve base having a passage, an annularouter wall and outwardly directed flanges forming a groove with theouter wall, a valve member operable to open and close said passage,means holding the valve member in assembled relation with the valvebase, a suturing member mounted on said base with a portion thereoflocated in said groove, said suturing member having means foraccommodating live heart tissue, a sleeve having opposite end portionsholding a section of said suturing member in said groove in uniformengagement with the outer wall and the flanges of the base, said endportions having means to accommodate means providing continuouscontracting forces, means located around said sleeve applying acontracting and holding force on said sleeve, said means located aroundsaid sleeve including means cooperating with the means of the oppositeend portions providing continuous contracting forces on said endportions.

18. The heart valve of claim 17 wherein: the end portions are enlargedbeads having outwardly open groove means, said means cooperating withthe end portions being located in said grooves.

19. The heart valve of claim 17 wherein: the means located around thesleeve comprise cord means wrapped around the sleeve.

20. The heart valve of claim 17 includingz'a core of plastic materialsurrounding the sleeve and enclosed with the means for accommodatinglive tissues.

21. The heart valve of claim 17 wherein: said sleeve has outwardly opengrooves in the opposite end portions thereof, said means cooperatingwith the end portions being located in said grooves.

l l l 33 5 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PatentNo. 3,859 ,668 Dated H January 14, 1975 Inventor(s) Lawrence Anderson Itis certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 1, line 45, "would" should be --wound-.

Column 2, line 55,, "section" should be -sectional- Column 3, line 5,"device" should be devices- Column 10, line 12, "materiall" should be--material--.

Signed-and sealedthis 3rd day 0f June 1975* (32AM Att'est:

C. MARSHALL DANN RUTH Cl MASQN Commissioner of Patents Attesting Officerand Trademarks

1. A suturing member mountable on a member having an outer annular walland outwardly directed flanges forming an annular groove and connectableto tissues of a living creature comprising: cover means including porousmaterial for accommodating live tissues to form a union between thesuturing member and the tissues, a continuous sleeve of heat shrunkplastic material located around an inner portion of said cover means tohold the suturing member in the annular groove in engagement with theannular wall and flanges of the member, said sleeve having opposite endportions with means to accommodate contracting force applying means,means located around said sleeve to apply a continuous contracting forceon the sleeve, said means including means cooperating with the means onthe opposite end portions of the sleeve to force the end portions towardthe flanges, and a core of cured plastic material located adjacent saidsleeve and surrounded by said cover means.
 2. The suturing member ofclaim 1 wherein: said core material has an outer surface secured to theinner surface of the cover means.
 3. A suturing member connectable totissues of a living creature comprising: cover means including porousmaterial for accommodating live tissues to form a union between themember and the tissues, a sleeve of heat shrunk plastic material locatedaround an inner portion of said cover means, cord means wrapped aroundsaid sleeve, and a core of cured plastic material located adjacent saidsleeve and surrounded by said cover means, said sleeve having annularoutwardly open grooves in the opposite end portions thereof, andcontinuous contracting means located in said grooves.
 4. A suturingmember connectable to tissues of a living creature comprising: covermeans including porous material for accommodating live tissues to form aunion between the member and the tissues, a sleeve of heat shrunkplastic material located around an inner portion of said cover means,cord means wrapped around said sleeve, and a core of cured plasticmaterial located adjacent said Sleeve and surrounded by said covermeans, said sleeve having annular enlarged bead means on the oppositeend portions thereof, said bead means having outwardly open groovemeans, means located in said groove means providing a contracting forceon the opposite end portions of said sleeve, said cord means beinglocated and confined to the space between said bead means.
 5. A heartvalve comprising: a valve base having spaced outwardly directed flangesand an outer wall between said flanges forming a groove, a valve memberselectively movable relative to said base to open and closed positions,means holding the valve member in assembled relation with the base, asuturing member mounted on said base with a portion thereof located insaid groove, said suturing member having cover means including porousmaterial for accommodating live heart tissue to form a union between thesuturing member and the heart tissue, a sleeve of heat shrunk materiallholding a section of said cover means in said groove and in uniformengagement with the flanges and outer wall of the base, said sleevehaving opposite end portions with means to accommodate contracting forceapplying means, cord means around said sleeve providing a contractingand holding force on said sleeve, said cord means including meanscooperating with the means on the opposite end portions of the sleeve toforce the end portions toward the flanges, and a core of cured plasticmaterial surrounding said sleeve and enclosed within said cover means.6. The heart valve of claim 5 wherein: said core of plastic material issecured to the cover means and cord means.
 7. A suturing memberconnectable to tissues of a living creature comprising: cover meansincluding porous material for accommodating live tissues to form a unionbetween the member and the tissues, a continuous annular sleeve of heatshrunk plastic material located around an inner portion of said covermeans, said sleeve having annular outwardly open grooves in the oppositeend portions thereof, and continuous contracting means located in saidgrooves, and cord means wrapped around said sleeve.
 8. A heart valvecomprising: a valve base, a valve member selectively movable relative tosaid base to open and closed positions, means holding the valve memberin assembled relation with the base, a suturing member mounted on anouter portion of said base, said suturing member having cover meansincluding porous material for accommodating live heart tissue to form aunion between the suturing member and the heart tissue, a sleeve of heatshrunk material holding a section of said cover in engagement with theouter portion of the base, said sleeve having annular outwardly opengrooves in the opposite end portions thereof, continuous contractingmeans located in said grooves, cord means around said sleeve providing acontracting and holding force on said sleeve, and a core of curedplastic material surrounding said sleeve and enclosed with said covermeans.
 9. A heart valve comprising: a valve base, a valve memberselectively movable relative to said base to open and closed positions,means holding the valve member in assembled relation with the base, asuturing member mounted on the outer portion of said base, said suturingmember having cover means including porous material for accommodatinglive tissue for form a union between the suturing member and the hearttissue, a sleeve of heat shrunk material holding a section of said coverin engagement with the outer portion of the base, said sleeve havingannular enlarged bead means on the opposite end portions thereof, saidbead means having outwardly open groove means, means located in saidgroove means providing a contracting force on the opposite end portionsof said sleeve, cord means around said sleeve providing a contractingand holding force on said sleeve, said cord means being located andconfined to the space between said bead means, and a core of curedplastic material surrounding said sleeve and enclosed within said covermeans.
 10. A suturing member connectable to tissues of a living creaturecomprising: means for accommodating live tissues to form a union betweenthe member and the tissues, a continuous annular sleeve located aroundan inner portion of said means, said sleeve having opposite endportions, said end portions having means to accommodate means providingcontinuous contracting forces on said end portions, and means locatedaround said sleeve providing a contracting and holding force on saidsleeve, said means located around said sleeve including meanscooperating with the means of the opposite end portions providingcontinuous contracting forces on said end portions.
 11. The suturingmember of claim 10 wherein: the end portions are enlarged beads havingoutwardly open groove means, said means cooperating with the endportions being located in said grooves.
 12. The suturing member of claim10 wherein: the means located around the sleeve comprise cord meanswrapped around the sleeve.
 13. The suturing member of claim 10including: a core of plastic material surrounding the sleeve andenclosed with the means for accommodating live tissues.
 14. A suturingmember connectable to tissues of a living creature comprising: covermeans including porous material for accommodating live tissues to form aunion between the member and the tissues, a continuous annular sleeve ofheat shrunk plastic material located around an inner portion of saidcover means, said sleeve having annular enlarged bead means on theopposite end portions thereof, said bead means having outwardly opengroove means, means located in said groove means providing a contractingforce on the opposite end portions of said sleeve, and cord meanswrapped around said sleeve, said cord means being located and confinedto the space between said bead means.
 15. A suturing member connectableto tissues of a living creature comprising: means for accommodating livetissues to form a union between the member and the tissues, a sleevelocated around an inner portion of said means, means located about saidsleeve to apply a continuous contracting force on said sleeve, saidsleeve having outwardly open grooves in the opposite end portionsthereof, and means located in said grooves applying a continuous forceon said end portions.
 16. The suturing member of claim 15 wherein: saidsleeve has annular enlarged bead means on the opposite end portionsthereof, said bead means having the outwardly open grooves.
 17. A heartvalve comprising: a valve base having a passage, an annular outer walland outwardly directed flanges forming a groove with the outer wall, avalve member operable to open and close said passage, means holding thevalve member in assembled relation with the valve base, a suturingmember mounted on said base with a portion thereof located in saidgroove, said suturing member having means for accommodating live hearttissue, a sleeve having opposite end portions holding a section of saidsuturing member in said groove in uniform engagement with the outer walland the flanges of the base, said end portions having means toaccommodate means providing continuous contracting forces, means locatedaround said sleeve applying a contracting and holding force on saidsleeve, said means located around said sleeve including meanscooperating with the means of the opposite end portions providingcontinuous contracting forces on said end portions.
 18. The heart valveof claim 17 wherein: the end portions are enlarged beads havingoutwardly open groove means, said means cooperating with the endportions being located in said grooves.
 19. The heart valve of claim 17wherein: the means located around the sleeve comprise cord means wrappedaround the sleeve.
 20. The heart valve of claim 17 including: a core ofplastic material surrounding the sleeve and enclosed with the means foraccommodating live tissues.
 21. The heart valve of claim 17 wherein:said sleeve has outwardly open grooves in the opposite end Portionsthereof, said means cooperating with the end portions being located insaid grooves.